Prospective Sky Guides (Fixed Wing Aircraft)

The Need for the Research

The demand for air transport is forecast to increase between twice and three time present day levels by the year 2030 [1].  This will put increasing strain on an already crowded airspace system in terms of both the economics and safety of air transport operations.  The major cause of this problem is seen as the inflexibility of the present day air traffic management (ATM) system [2].  Aircraft operators are therefore forced to fly fixed routes, often at fixed speeds at a number of pre-determined altitudes.

Flight-deck technology has, to some degree, raced ahead of the ground based system used to support it.  Modern jet transport aircraft are equipped with on-board computers that provide a Flight Management System (FMS).  These can provide functions that will automatically fly the aircraft along more efficient trajectories point to point within defined accuracy tolerances.  These so-called RNAV operations (Required Area Navigation) are slowly being introduced but their utilisation is not yet widespread or optimal.  To fully adopt the flexible ATM system, the airways system would have to be abandoned.

In a parallel development, satellite and data link technologies (i.e. Global Positioning System, GPS) can now provide the capability for aircraft to broadcast their intended route and negotiate efficient trajectories with ATM computers taking into account other relevant traffic.  The use of modern technology to make global air transport operations more efficient (including, for example, investigation into the utilisation of other aircraft platforms to reduce capacity problems at busy airports) is the subject of a number of studies including Ref. [3] (OPTIMAL).

The danger in rushing to use technology in any realm of human endeavour is that the human element is either forgotten or over-relied upon.  Pilots are highly trained individuals and one of their primary drivers is the safe conduct of any flight.  Reducing aircraft separations and allowing flight in non-defined airways has the potential to reduce flight safety.  In such an environment, it is incumbent upon flight-deck equipment providers to present information about both the aircraft status and the surrounding environment to an aircraft’s flight crew that will allow a rapid and intuitive assessment of the safety and appropriateness of the current situation.  Such a system must allow easy manual intervention or the simple monitoring of the automatic processes.

For as long as there has been powered aircraft there have been attempts to provide their pilots with additional information to allow the flight to be conducted in a more controlled and safe manner.  Pilots of large jet transport aircraft, at least, no longer fly by the ‘seat-of-the-pants’ but are ‘system-information-monitors’ [4].  Flight control system technology is mature enough to allow automatic take-off, en-route flight and landings to be carried out without the need of pilot intervention.  The pilot monitors the actions of the automation, ready to intervene and take control if a system failure occurs.  Failure of the automatic systems must not lead to a catastrophic loss of the aircraft or those on board and aircrew are legally required to maintain their manual flying skills.  Manual flight is still performed but usually with reference to a Flight Director (FD).  The FD is a display that provides the pilot with automated steering information.  All of this has led to concerns that [2]:

  1. whilst manual workload has decreased, mental workload has increased [5,6];
  2. human beings do not perform at all well in monitoring task situations [7];
  3. removal of the crew from the control loop of the aircraft reduces their ability to maintain an awareness of the aircraft’s situation [8];
  4. flight-deck technology has become so complex that it is difficult for flight crew to understand the principles on which the automation is operating [9] and
  5. the extensive use of automation has reduced the proficiency of pilots to perform flight tasks manually [7].
It is clear that there is a conflict between the desire to use increasingly sophisticated automation to facilitate more efficient air transport and the current level of understanding of how aircrew will be able to safely be part of and utilise such systems.  The most common question in modern cockpits is reported to be ‘what’s it doing now ?’ [10].  It was therefore considered timely to take a fresh look at how human crew use their senses to guide an aircraft through its environment and apply this learning to the design and development of the flight deck systems of the future.  This task was performed using the Ecological Approach to Motion Perception as a guide.